<script lang="ts" setup name="GoodsImage">
import { useMouseInElement } from '@vueuse/core';
import { computed, ref } from 'vue';

defineProps<{
  images: string[]
}>()

const active = ref(0) // 当前显示的图片的下标

const target = ref(null) // 放大镜的主体

// isOutside: 鼠标是否在当前的元素之外
const { isOutside, elementX, elementY } = useMouseInElement(target)

const position = computed(()=>{
  let x = elementX.value - 100
  let y = elementY.value - 100
  if(x<0){ x = 0}
  if(y<0){ y = 0}
  if(x>200){ x = 200}
  if(y>200){ y = 200}

  return {
    x: x,
    y: y
  }
})
</script>

<template>
  <div class="goods-image">
    <!-- 显示在右侧的放大之后的区域 -->
    <div 
      class="large"
      v-show="!isOutside"
      :style="[{backgroundImage:`url(${images[active]})`, backgroundPosition: `-${position.x*2}px -${position.y*2}px`}]"></div>

    <!-- 主体 ref="target" -->
    <div class="middle" ref="target">
      <img :src="images[active]" alt="" />
      <!-- 移动遮罩 -->
      <div class="layer" v-show="isOutside===false" :style="{ left:position.x+'px', top:position.y+'px' }"></div>
    </div>

    <ul class="small">
      <li
        v-for="(item,idx) in images"
        @mouseenter="active=idx"
        :key="idx"
        :class="{active: idx === active }">
        <img
          :src="item"
          alt=""
        />
      </li>
    </ul>
  </div>
</template>

<style scoped lang="less">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  z-index: 500;
  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    background-repeat: no-repeat;
    // 放大一倍
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }
  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
    position: relative;
    cursor: move;
    .layer {
      width: 200px;
      height: 200px;
      background: rgba(0,0,0,.2);
      left: 0;
      top: 0;
      // 可以移动
      position: absolute;
    }
  }
  .small {
    width: 80px;
    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      &:hover,
      &.active {
        border: 2px solid @xtxColor;
      }
    }
  }
}
</style>